Recrystallization is one way of isolating an ionic compound from a solution.

If several ionic compounds are present in an aqueous solution, 

then a precipitation reaction may be performed to remove the unwanted ions.

In this experiment, 

a known amount of NaCl will be dissolved in some water,

and then recrystallized by boiling off the water.

You will learn to

To perform and master a recrystallization of an ionic compound

To write a procedure for a simple experiment

To calculate for percent error in an experiment

To understand how results affect percent error

To identify sources of error in experiments

A

Mass of salt (NaCl) used. Must be between 1 and 2 grams: 1.60 g

B

Mass of empty beaker before you start: 144.07 g

C

Mass of beaker with recrystallized NaCl: 145.61 g

D

Mass of recrystallized NaCl (C minus B): 1.54 g

E

Volume of water added to dissolve NaCl: 25mL

A

Mass of salt (NaCl) used. Must be between 1 and 2 grams: 1.66 g

B

Mass of empty beaker before you start: 144.07 g

C

Mass of beaker with recrystallized NaCl: 145.56 g

D

Mass of recrystallized NaCl (C minus B): 1.54 g

E

Volume of water added to dissolve NaCi: 25mL

2. If your percent error was positive, what logical sources of error might have been the cause? Explain. Answer this question regardless of what your results were.

3. If your percent error was negative, what logical sources of error might have been the cause? Explain. Answer this question regardless of what your results were.

4. Which ESLR or ESLR’s were  addressed in the activity? State the ESLR and explain why in a short paragraph.

A

Mass of salt (NaCl) used. Must be between 1 and 2 grams:1.60g

B

Mass of empty beaker before you start : 144.07g

C

Mass of beaker with recrystallized NaCl: 145.60g

D

Mass of recrystallized NaCl (C minus B): 1.53g

E

Volume of water added to dissolve NaCl: 25mL

2. If our percent error was positive, then it may be because some of the salt flew up and stuck to the watch glass.

3.If our pecent error was negative, then it may be because we didn't boil off all the water.

4. I think we were effective communicators who locate, interpret, evaluate, organize, process and present information using technology or appropriate resources. We evalutated the results of the expirement and then processed and presented the information using technology